4. never panic, and if somebody starts shooting at you dont go like WOMGMOMWOGMOG MY GEAR FRIENDLY FRENDLI FRENDLIIIIIIIIIII BRO WTF I DIDNT DU NOFING. If they already started shooting at you, they most likely looking to pvp, shoot them back. Keep this in mind in day z its just a matter of time till you lose all your shit, so you might aswell engage in a pvp fight to get more experienced.
5. i like this one the most. If you get the chance strap ppl down, take their gear if u want to, but don't kill them, interact.
These two points most of all i think. Don't worry about loosing your stuff you can usually have pretty good gear again in no time. That is actually some of the most fun is finding things.